The invention concerns a high wavelength laser device and more particularly a powerful laser tuneable at high wavelengths.
Tuneable lasers are known in the industry such as, for example, a laser based on a sapphire crystal doped with titanium which emits in a domain covering a window between 0.6 and 1.1 microns.
Devices are also known which include a Raman cell excited by a pump laser. The description of such a device can be found in French patent application no. 89 09303, filed on Jul. 11, 1989. Such a Raman cell is constituted of an enclosure containing a pressurized gas which can be hydrogen, deuterium or methane. This gas cell excited by a pump laser, for example a laser based on a sapphire crystal doped with titanium, enables a wave (Stokes wave) to be generated by non-linear interaction, whose wavelength can be tuned within a window between approximately 0.7 and 2 microns.
However certain applications may require a laser emitting at high wavelengths, such as the visible wavelengths, and tuneable in large wavelength ranges.